Electrocautery surgical scissors

ABSTRACT

A tissue-cutting apparatus includes first and second electrically conductive tissue-cutting blades coupled together about a common pivot for relative movement thereabout between open and closed positions, the first and second tissue-cutting blades, each having an elongated cutting edge with the cutting edges disposed to pass each other in contiguous relationship along the elongated cutting edges as the first and second relatively move from open toward closed positions, an electrode insulated from and attached spaced away from each of the first and second blades on a side thereof remote from the contiguous cutting edges, an electrode extension mounted on and connected to at least one of the electrodes on a side thereof remote from the cutting blade to extend in a direction toward the cutting edge of the associated blade, and conductors connected to the electrodes for supplying electrical signals thereto.

RELATED APPLICATION DATA

This application is a continuation of application Ser. No. 12/029,222, filed on Feb. 11, 2008, which is a continuation of application Ser. No. 10/851,051, filed on May 21, 2004, which is a continuation of application Ser. No. 10/071,940, filed on Feb. 5, 2002, now issued as U.S. Pat. No. 6,749,609, the disclosures of all of which are expressly incorporated by reference herein.

The subject matter of this application relates to the subject matter described in application Ser. No. 09/739,595, filed on Dec. 15, 2000, now issued as U.S. Pat. No. 6,506,207, which subject matter is expressly incorporated by reference herein.

FIELD

This application relates to surgical instruments incorporating scissors and to surgical scissors, and more particularly to surgical scissors having electrocautery electrodes disposed adjacent tissue-cutting blades for selective cauterization and shearing of tissue.

BACKGROUND

Endoscopic surgery commonly requires manual manipulation of surgical instruments that are introduced into a surgical site within a patient through elongated cannulas containing one or more interior lumens of slender cross section. Endoscopic surgery to harvest a saphenous vein usually involves an elongated cannula that is advanced along the course of the vein from an initial incision to form an anatomical space about the vein as connective tissue is dissected away from the vein.

Lateral branch vessels of the saphenous vein can be conveniently isolated and ligated within the anatomical space under endoscopic visualization using surgical scissors that can be positioned and manipulated through the elongated cannula. Such surgical procedures are commonly employed in the preparation of the saphenous vein for removal from within the anatomical space for use, for example, as a shunting or graft vessel in coronary bypass surgery.

Surgical scissors that are used to transect vessels within the confines of limited anatomical space formed along the course of the saphenous vein commonly incorporate electrodes on or near the tissue-shearing blades. Scissors of this type are suitable for monopolar or bipolar electrocauterization of tissue prior to transection of, for example, lateral side branches of the saphenous vein to be harvested. However, placement of the electrodes in relation to the tissue-shearing edges of the blades may inhibit proper operation of the blades to shear tissue and may inhibit thorough electrocauterization of a side branch vessel as the blades close during transection of the vessel.

SUMMARY

In accordance with some embodiments, surgical scissors include scissor blades mounted at the distal end of a slender body for manual manipulation under control of a lever mounted at the proximal end of the slender body. The scissor blades support electrodes that are positioned to supply electrical energy from external sources to cauterize tissue prior to shearing the cauterized tissue at a remote surgical site in a patient. The electrodes of various configurations are spaced from, and are electrically isolated from, the tissue-cutting blades (or at least from one such blade) in order to optimize both the ability to shear tissue as well as the ability to localize the electrocauterization of the tissue to be sheared within a wide angle of alignment of tissue relative to the blade.

Also, in accordance with some embodiments, a tissue-cutting apparatus includes first and second electrically conductive tissue-cutting blades coupled together about a common pivot for relative movement thereabout between open and closed positions, the first and second tissue-cutting blades, each having an elongated cutting edge with the cutting edges disposed to pass each other in contiguous relationship along the elongated cutting edges as the first and second relatively move from open toward closed positions, an electrode insulated from and attached spaced away from each of the first and second blades on a side thereof remote from the contiguous cutting edges, an electrode extension mounted on and connected to at least one of the electrodes on a side thereof remote from the cutting blade to extend in a direction toward the cutting edge of the associated blade, and conductors connected to the electrodes for supplying electrical signals thereto.

Surgical scissors in accordance with embodiments described herein may be incorporated into and form an integral part of more comprehensive surgical apparatus, for example, as illustrated and described with reference to FIGS. 8 and 9 of pending application Ser. No. 10/054,477, entitled “Vessel Harvesting Apparatus and Method”, filed on Jan. 18, 2002 by M. Stewart et al.

Other and further aspects and features will be evident from reading the following detailed description of the embodiments, which are intended to illustrate, not limit, the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the design and utility of embodiments, in which similar elements are referred to by common reference numerals. These drawings are not necessarily drawn to scale. In order to better appreciate how the above-recited and other advantages and objects are obtained, a more particular description of the embodiments will be rendered, which are illustrated in the accompanying drawings. These drawings depict only typical embodiments and are not therefore to be considered limiting of its scope.

FIG. 1 is a partial sectional view of conventional bipolar surgical scissors;

FIGS. 2, 3 and 4 are partial sectional views of embodiments of bipolar scissors;

FIGS. 5 and 6 are partial sectional views of other embodiments of bipolar scissors;

FIG. 7 is a partial sectional view of bipolar scissors modified in accordance with some embodiments;

FIGS. 8 a and 8 b are plan views of a set of bipolar scissor blades in accordance with some embodiments;

FIG. 9 is a pictorial side view of an embodiment of the bipolar scissor blades according to FIGS. 8 a and 8 b; and

FIG. 10 is a partial side view of another embodiment of bipolar scissors.

DESCRIPTION OF THE EMBODIMENTS

Various embodiments are described hereinafter with reference to the figures. It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the invention or as a limitation on the scope of the invention. In addition, an illustrated embodiment needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated.

Referring now to FIG. 1, there is shown a cross-sectional end view of conventional surgical scissors that include both shearing blades 9, 11 and electrically-conductive blade supports 13, 15 that carry in insulated manner the respective cutting blades 9, 11. In this configuration, the cutting blades 9, 11 are positioned against tissue (typically a lateral or side branch vessel of a main vessel such as a saphenous vein) in preparation for cutting the tissue prior to or coincident with contact being made with the tissue by the blade supports serving as electrodes 13, 15. As a result, electrocauterization of the tissue is not possible until either the cutting blades 9, 11 penetrate tissue sufficiently to engage the electrodes 13, 15, or the angle 17 of presentation of the tissue to the cutting blades 9, 11 is skewed sufficiently (by an obtuse angle in the illustration) for the electrodes 13, 15 to contact the tissue prior to contact therewith by the shearing blades 9, 11, or the tissue is manipulated to conform to the irregular surfaces by pressing the scissors against the tissue.

In accordance with one embodiment as illustrated in FIG. 2, an outer set of blade supports 19, 21 serve as bipolar electrodes and also support respective cutting blades 23, 25 via insulated attachment 27 to the inner or facing surfaces of the blade supports 19, 21. A mixture of tiny glass beads and epoxy provide a suitable insulating and attaching layer 27 for securing the blades 23, 25 to the respective blade supports 19, 21. The cutting blades 23, 25 are thus disposed to pass by each other along an advancing point of contact along the contiguous cutting edges as the blades 23, 25 move toward and past each other in scissor-like manner. The blade supports 19, 21 each include a conductive extension 29, 31 that protrudes inwardly toward the opposite blade support to elevate the level or points of contact thereof with tissue above the level or points of contact of the cutting blades 21, 23 with the tissue. In this configuration, the angle 30 of presentation of the tissue to the cutting blades 23, 25 and electrodes 19, 21 within which electrical contact can be made to tissue prior to contact therewith by the cutting blades is much broader, to an extreme limit as illustrated in FIG. 3. This facilitates the surgeon positioning such bipolar scissors relative to a side branch vessel 33 at a diversity of angles for electrocauterizing and then transecting the vessel. In preferred embodiments, various configurations of extensions 29, 31 on each of the electrodes 19, 21 extend in directions toward the opposite ones of the electrodes to elevate the level of electrical contacts with tissue by about 0.018″ to about 0.030″ above the level of the cutting edges of the blades 23, 25, as illustrated in the sectional views of FIGS. 2-6. The electrode extensions 29 in these various illustrated embodiments may be welded onto the facing edges of the electrodes 19, 21 that serve as blade supports for the respective cutting blades 23, 25, or may be formed as part of the electrode-blade support 19, 21, as shown in the plan views of FIGS. 8 a and 8 b.

Referring now to FIG. 5, the L-shaped extension 29 on the blade support 29, as shown in sectional view, is welded or otherwise conductively joined to each blade support 19. The tissue-contacting edge 40 is thus elevated by about 0.018″ to about 0.030″ while also reducing the spacing 42 between the inside edge of the electrode 43 and the cutting edge 41 of cutting blade 23. This increases the angle of presentation of the tissue to the cutting blades, as previously described with reference to FIG. 3. Of course, similar extensions 29 may be attached in mirror symmetry to each of the blade supports of a scissor structure in accordance with some embodiments to enhance the angle of presentation of tissue to the cutting blades.

Referring now to FIG. 6, there is shown a sectional view of another conductive extension 29 that is conductively attached to the back side of the blade support 19. In this configuration, the inside edge 41 of the cutting blade 23 is spaced 42 from the protruding inside edge of the extension 29 at a distance that allows tissue to be compressed in cauterizing or cutting action in conformity with irregular surfaces involved. Specifically, this structure facilitates presentation of tissue to the cutting edge 41 of the blade 23 at an angle of approximately 90.degree. for optimized cutting and cauterizing operation.

Referring now to the sectional view of FIG. 7, conventional bipolar scissor blades 9, 11 that commonly extend inwardly or beyond the tissue-contacting edge of the attached electrodes 13, 15 may be electrically configured differently to broaden the angle of presentation within which bipolar electrodes 9, 15 and 13 may first contact tissue prior to the blades 9, 11 making tissue-shearing contact. Specifically, electrode 15 and blade 9 are electrically coupled together 34 to circumvent the electrical insulating properties of layer 27, while the electrode 13 of one polarity remains electrically insulated from the structure of blades 9, 11 and electrode 15 of opposite polarity. This configuration enhances the benefit of the blade 9, serving as an electrode, protruding inwardly toward the opposite electrode 13, and thus enhances the angle of presentation within which tissue such as a side branch vessel may be oriented relative to the blades and electrodes for electrocauterization prior to transection of the vessel.

This configuration also facilitates formation of current conduction paths through tissue in contact with the structure, for example, from blade support or electrode 13 to the cutting blade 11, or to cutting blade 9 or to blade support 15. Alternatively, the structure of blade support 15 and insulating layer 27 and cutting blade 9 and conductive link 34 can be configured as a single conductive cutting blade.

Referring now to FIGS. 8 a and 8 b, there are shown plan views of a complementary set of left and right electrode-blade supports 19, 21 that include respective extensions or protrusions 29, 31 from the facing edges thereof. These extensions or protrusions 29, 31 protrude by about 0.018″ and extend along about ⅔, or a major portion, of the proximal sections of the facing edges relative to pivot axes 36. Of course, the extensions or protrusions from the facing edges may extend out to the distal ends of the associated supports. This configuration expands the angle of presentation of tissue to the blades and electrodes within which electrocauterizing contact with the tissue occurs prior to shearing contact therewith, for reasons as previously described herein, as the electrode-blade supports 19, 21 are rotated about the pivot axes 36 toward each other in scissor-like manner. These electrodes 19, 21 and associated cutting blades 23, 25 may be curved, as shown in FIG. 9, and the cutting edges of curved blades attached thereto may be serrated to enhance tissue-cutting capability.

In another embodiment as illustrated in FIG. 10, the electrode-blade supports 19, 21 include arcurate conductive members 37, 39 welded to, or otherwise electrically and mechanically attached to, the outer surfaces or facing edges of the electrodes 19, 21. Such arcuate members 37, 39 facilitate electrical contact with tissue such as a side-branch vessel over a wide range of presentation angles relative to the electrodes 19, 21. Cutting blades (not shown in FIG. 10) may be attached in insulated manner to the inside facing surfaces of the electrodes 19, 21 in the manner as previously described herein to facilitate cutting tissue following electrocauterization during the closing of the electrodes in scissor-like manner about the pivot axis 36.

Therefore, the bipolar tissue-cauterizing and cutting instruments according to some embodiments described herein provide reliable electrical contact with tissue to be cut over a broad range of angles of presentation of the tissue to the electrodes. This assures controlled electrocauterization prior to shearing or transection of the cauterized tissue. Various configurations of blade supports that serve as electrodes and that support cutting blades in facing, scissor-like engagement along contiguous cutting edges assure reliable electrical contact for electrocauterization of tissue prior to shearing of the cauterized tissue.

Although particular embodiments have been shown and described, it will be understood that they are not intended to limit the present inventions, and it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present inventions. The specification and drawings are, accordingly, to be regarded in an illustrative rather than restrictive sense. The present inventions are intended to cover alternatives, modifications, and equivalents, which may be included within the spirit and scope of the present inventions as defined by the claims. 

1-3. (canceled)
 4. A tissue cutting apparatus, comprising: a first jaw; a second jaw that is moveable relative to the first jaw; a first electrode coupled to the first jaw, the first electrode having a first electrode portion for contacting tissue; a second electrode coupled to the second jaw, the second electrode having a second electrode portion for contacting the tissue; a first tissue cutting element located next to the first electrode; and wherein the first electrode portion of the electrode is offset from the first tissue cutting element such that when the first and the second jaws close towards each other, the first electrode portion of the electrode contacts the tissue first before the first cutting element contacts the tissue.
 5. The tissue cutting apparatus of claim 4, wherein the tissue cutting element is coupled to the first jaw.
 6. The tissue cutting apparatus of claim 4, wherein the tissue cutting element is fixed in position relative to the first electrode.
 7. The tissue cutting apparatus of claim 4, wherein the tissue cutting element comprises a blade.
 8. The tissue cutting apparatus of claim 4, wherein the first tissue cutting element has a portion for contacting the tissue, and the first electrode portion of the electrode is offset from the portion of the first tissue cutting element by a distance that is measured in a direction of movement by the first jaw.
 9. The tissue cutting apparatus of claim 8, wherein the distance is less than 0.03 inch.
 10. The tissue cutting apparatus of claim 4, further comprising a second tissue cutting element, wherein the first tissue cutting element is coupled to the first jaw, and the second tissue cutting element is coupled to the second jaw.
 11. The tissue cutting apparatus of claim 10, wherein the second electrode portion of the second electrode is offset from the second tissue cutting element such that when the first and the second jaws close towards each other, the first and the second electrodes contact the tissue first before the first and the second cutting elements contact the tissue.
 12. The tissue cutting apparatus of claim 10, wherein a first lateral distance between the first and the second electrodes measured in a direction that is perpendicular to a direction of movement by the first jaw is larger than a second lateral distance between the first and the second tissue cutting elements.
 13. The tissue cutting apparatus of claim 4, wherein the first jaw comprises an insulative structure to which the first electrode and the first tissue cutting element is coupled.
 14. The tissue cutting apparatus of claim 4, wherein the first and the second jaws are configured to operate on a vessel, and the tissue comprises a segment of the vessel.
 15. The tissue cutting apparatus of claim 4, wherein the first electrode is located closer to an outer side of the first jaw than the first tissue cutting element.
 16. The tissue cutting apparatus of claim 4, wherein a spacing between the first and the second electrodes is minimized, the spacing being measured in a lateral direction that is perpendicular to a direction of movement of the first jaw.
 17. A tissue cutting apparatus, comprising: a first jaw; a second jaw that is rotatable relative to the first jaw; a first electrode coupled to the first jaw, the first electrode having a first electrode portion for contacting tissue; a second electrode coupled to the second jaw, the second electrode having a second electrode portion for contacting the tissue; a first tissue cutting element located next to the first electrode; and wherein the first electrode portion of the electrode is offset from the first tissue cutting element such that when a tissue is placed between the first and the second jaws, a first distance between the tissue and the first electrode is less than a second distance between the tissue and the first cutting element.
 18. The tissue cutting apparatus of claim 17, wherein the tissue cutting element is coupled to the first jaw.
 19. The tissue cutting apparatus of claim 17, wherein the tissue cutting element is fixed in position relative to the first electrode.
 20. The tissue cutting apparatus of claim 17, wherein the tissue cutting element comprises a blade.
 21. The tissue cutting apparatus of claim 17, wherein the first tissue cutting element has a portion for contacting the tissue, and the first electrode portion of the electrode is offset from the portion of the first tissue cutting element by a distance that is measured in a direction of movement by the first jaw.
 22. The tissue cutting apparatus of claim 21, wherein the distance is less than 0.03 inch.
 23. The tissue cutting apparatus of claim 17, further comprising a second tissue cutting element, wherein the first tissue cutting element is coupled to the first jaw, and the second tissue cutting element is coupled to the second jaw.
 24. The tissue cutting apparatus of claim 23, wherein the second electrode portion of the second electrode is offset from the second tissue cutting element such that when the first and second jaws close towards each other, the first and the second electrodes contact the tissue first before the first and the second cutting elements contact the tissue.
 25. The tissue cutting apparatus of claim 23, wherein a first lateral distance between the first and the second electrodes measured in a direction that is perpendicular to a direction of movement by the first jaw is larger than a second lateral distance between the first and the second tissue cutting elements.
 26. The tissue cutting apparatus of claim 17, wherein the first jaw comprises an insulative structure to which the first electrode and the first tissue cutting element is coupled.
 27. The tissue cutting apparatus of claim 17, wherein the first and the second jaws are configured to operate on a vessel, and the tissue comprises a segment of the vessel.
 28. The tissue cutting apparatus of claim 17, wherein the first electrode is located closer to an outer side of the first jaw than the first tissue cutting element.
 29. The tissue cutting apparatus of claim 17, wherein a spacing between the first and the second electrodes is minimized, the spacing being measured in a lateral direction that is perpendicular to a direction of movement of the first jaw. 